A major effort of this laboratory has thus been directed toward the elucidation of the enzymatic basis for the synthesis of RNA and protein. The specific aims of the research proposed are directed toward the elucidation of the following major areas of interest: (1) The bacteriophage T3-induced DNA-dependent RNA polymerase is being characterized, with particular regard to the control mechanisms operating at the level of initiation and termination of RNA synthesis using T3 DNA template. The following studies are being carried out: (a) determination of the oligonucleotide sequences on the DNA template that determine the initiation and the termination specificities of this polymerase; (b) identification of protein factor(s) from T3-infected cells that may be required in the T3 RNA polymerase reaction to give rise to RNA species that are identical in size and in initiation and termination sequences to the corresponding in vivo mRNAs. Such factor(s) must exist since in vitro transcripts are much larger in size than the in vivo transcripts isolated from T3 infected cells. Thus, the purified in vitro system either lacks additional factor(s) necessary for proper termination of RNA synthesis by T3 RNA polymerase; alternatively post transcriptional cleavage of large-size in vitro transcripts to smaller discrete-size classes of mRNAs may occur. (2) Further studies on the mechanism of initiation of protein synthesis will be carried out to further elucidate the role of each of the initiation protein factors - IF1, IF2 and IF3 - in the initiation complex formation.